I’ve used a small pump like a maxijet to vacuum out detritus, either with a 3D printed nozzle or just a piece of tubing. Problem for me is that the intake gets clogged and the impeller tanged too fast, like every 10 seconds or so. I spend more time cleaning the pump than pumping with it. That’s what I like better about the hand pump, no impeller to tangle and no screen to clog.I have no mechanical filtration and have run many years like that.
for sump cleaning I use a pump and vacuum out the stuff in the various sections, mostly the return every time I do a WC every other week.
vivid creative aquatics has a nice pump attachment for the vacuuming.